zsh-workers
 help / color / mirror / code / Atom feed
From: Oliver Kiddle <opk@zsh.org>
To: Bart Schaefer <schaefer@brasslantern.com>
Cc: Zsh workers <zsh-workers@zsh.org>
Subject: Re: [PATCH 1/3]: Add named references
Date: Thu, 09 Feb 2023 03:01:00 +0100	[thread overview]
Message-ID: <25878-1675908060.317862@x_tj.49MY.g4Qe> (raw)
In-Reply-To: <12608-1675903622.800470@Xj82.e3y1.svhG>

This isn't a self-reference because the local levels would be different.
And "self reference" in the error message should be hyphenated.
  typeset -n ref=var
  foo() { typeset -n var=ref }
  foo
  foo:typeset:1: var: invalid self reference
With -g it would be, however.

I wrote:
> On the subject references to array elements, it does seem both powerful and
> dangerous that subscripts are evaluated on reference. The subscript

This is fairly sane:
  typeset -n ref1=arr[ref2] 
  typeset -n ref2=ref1     
  echo $ref1
  zsh: math recursion limit exceeded: ref2

This seems useful:
  arr=()
  typeset -n ref=arr[1,0]
  ref=4
  ref=5

Similar:
  idx=1
  typeset -n ref=arr[idx++]
  echo $ref $ref

This is where I worry about security:
  arr=( 1 2 3 4)
  typeset -n ref='arr[$(echo 4)]'
  echo $ref
  typeset -p ref  # it was only evaluated late thanks to quotes
Maybe the code should have a safer mode for subscript evaluation. This
could be useful but it is asking for trouble.

Also can see this being useful:
  str='one two three'
  typeset -n ref=str[(w)2]
  ref=zwei

We already talked about this error message. But now it is a substring.
  export ref
  export: ref: can't change type of a named reference

Oliver


  reply	other threads:[~2023-02-09  2:04 UTC|newest]

Thread overview: 48+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-02-06  2:21 Bart Schaefer
2023-02-08  3:45 ` Oliver Kiddle
2023-02-08  4:59   ` Bart Schaefer
2023-02-08 23:16     ` Bart Schaefer
2023-02-09  0:47     ` Oliver Kiddle
2023-02-09  2:01       ` Oliver Kiddle [this message]
2023-02-09  5:45         ` Bart Schaefer
2023-02-09  4:49       ` Bart Schaefer
2023-02-09 20:49         ` Oliver Kiddle
2023-02-09 23:07           ` Bart Schaefer
2023-02-11  3:04             ` Bart Schaefer
2023-02-11  3:55               ` Bart Schaefer
2023-02-11  5:36                 ` Speaking of dangerous referents Bart Schaefer
2023-02-12  8:00                   ` Oliver Kiddle
2023-02-12  8:34                     ` Bart Schaefer
2023-02-11  7:02               ` [PATCH 1/3]: Add named references Oliver Kiddle
2023-02-11  7:45                 ` Bart Schaefer
2023-02-11 23:43                   ` Bart Schaefer
2023-02-11 23:45                     ` Bart Schaefer
2023-02-12  7:38                     ` Oliver Kiddle
2024-02-11  7:00                   ` Stephane Chazelas
2024-02-11 16:14                     ` Bart Schaefer
2024-02-11 16:42                       ` Bart Schaefer
2024-02-18  3:26                       ` Up-scope named references, vs. ksh Bart Schaefer
2024-02-20 21:05                         ` Stephane Chazelas
2024-02-20 22:30                           ` Bart Schaefer
2024-02-21 20:12                             ` Stephane Chazelas
2024-02-29  5:16                               ` Bart Schaefer
2024-03-01 18:22                                 ` Stephane Chazelas
2024-03-01 20:34                                   ` Bart Schaefer
2024-03-02  7:29                                     ` Bart Schaefer
2024-03-02 23:55                                       ` [PATCH] "typeset -nu" (was Re: Up-scope named references, vs. ksh) Bart Schaefer
2024-03-01 23:28                                   ` Up-scope named references, vs. ksh Bart Schaefer
2024-03-03 13:44                                     ` Stephane Chazelas
2024-03-03 19:04                                       ` Bart Schaefer
2024-03-03 20:27                                         ` Stephane Chazelas
2024-03-03 22:58                                           ` Bart Schaefer
2024-03-04 19:59                                             ` Stephane Chazelas
2024-03-05  1:05                                             ` Oliver Kiddle
2024-03-05  2:53                                               ` Bart Schaefer
2024-03-05  5:43                                                 ` Mikael Magnusson
2024-03-05  6:30                                                   ` Stephane Chazelas
2024-03-06  5:04                                                     ` [PATCH] local vs. nameref scoping (was Re: Up-scope named references, vs. ksh) Bart Schaefer
2023-02-12  9:02             ` [PATCH 1/3]: Add named references Oliver Kiddle
2023-02-12 18:59               ` Bart Schaefer
2023-02-12 19:45                 ` PM_* flags in zsh.h (was Re: [PATCH 1/3]: Add named references) Bart Schaefer
2023-02-12 21:01                   ` Oliver Kiddle
2023-02-12 22:54                 ` [PATCH 1/3]: Add named references Oliver Kiddle

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=25878-1675908060.317862@x_tj.49MY.g4Qe \
    --to=opk@zsh.org \
    --cc=schaefer@brasslantern.com \
    --cc=zsh-workers@zsh.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
Code repositories for project(s) associated with this public inbox

	https://git.vuxu.org/mirror/zsh/

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).